As well known, in conventional gas turbines, rotating machines typically have a rotor which has several rotor blade rows with a plurality of rotor blades, and generally also at least one rotor heat shield composed by a plurality of heat shield elements, wherein the rotor heat shield is arranged axially between two adjacent rotor blade rows.
According to current practise, the heat shield elements are inserted sequentially into a correspondent groove engraved into the rotor assembly, such to form a circumferential heat shield. In particular, each heat shield element is circumferentially fixed by means of a lug disposed on a neighbouring blade, which is accommodated in a receiving slot formed on the heat shield element. This connection is established at outer diameters (where large circumferential forces are involved), close to hot gas path (typically hotter metal temperature). Therefore, in the consideration that each rotor shield element is connected to a correspondent blade, the number of shield elements has to be somehow dependent on the number of the blades, that is the shield elements are in the same number, or half, or a third and so on.
However, current design presents a number of drawbacks. In fact, the presence of connecting lugs on the blades and corresponding receiving slots on heat shield elements determine a rather complex design to be carried out for both components. Furthermore, the lugs entail an undesirable weight increase of the blades.
Moreover, as the fixation is done at outer diameters of the machine, significant loads are transferred at the contact surfaces.
The present invention addresses these technical problems.